This invention relates to vacuum cleaners and more particularly to vacuum cleaners capable of operating with either air or with air and liquid and still more particularly to a portable hand held wet-dry vacuum cleaner which is operable over a wide range of angular orientations while satisfactorily handling liquid as the cleaning medium.
The wet-dry vacuum cleaner of the present invention is an improvement over the inventions of my prior U.S. Pat. Nos. 4,536,914 and 4,542,557 which issued Aug. 27, 1985 and Sept. 24, 1985, respectively. Those patents disclose portable, hand-held wet-dry vacuum cleaners which are generally capable of handling liquid as the cleaning medium over a wide range of angular orientations. The present invention also performs that same function, but does so in a different and improved manner.
My prior Pat. No. 4,542,557 discloses a wet-dry vacuum cleaner comprising a housing and a canister removably affixed to the front end thereof, and a handle at the back end thereof. The housing contains a blower or impeller, and a shaft imparts rotation to the blower to create a partial vacuum which draws air into the housing. The canister has a nozzle with an air intake port or spout at the end of the canister remote from the housing and an exit port and a diverter within the canister. A conduit which is located forwardly of and axially diagonal with the blower has an entry port located at the region of an interface between the housing and the canister, and an air filter covers the entry port for entrapping particulate matter which might otherwise be drawn into the conduit by the passage of air toward the blower. Air so drawn into the conduit passes the blower and is exhausted from the housing via exhaust vents at the bottom of the housing. Covering the opposite side of the filter from the conduit is an inlet chamber having an entry port with an opening which is laterally offset with respect to the diverter. The part of the interior of the canister which is forward of the filter and which is otherwise unoccupied provides a storage chamber, and the diverter diverts incoming liquid into the storage chamber, away from the air entry port opening, so that incoming liquid (with entrained dirt) is deflected away from the flow of the air stream which goes through the filter. When the vacuum cleaner is operated in the angular orientation with the air inlet opening of the nozzle facing vertically upwardly, the effective volume of the storage chamber is reduced to the volume thereof below the opening of the air entry port. If the liquid level were to rise above the air entry port opening, the liquid would enter, by gravity, into the inlet chamber, would pass through the filter and into the blower. From there, some of the liquid would pass out through the exhaust vents, creating a very messy situation, and some of the liquid would gain access to the motor, thus possibly shortening the life of the motor and causing danger of electrical shock to the user.
The present invention overcomes the aforesaid problem of the prior art in a manner which is at the same time simple and inexpensive.
Accordingly, it is an important object of the present invention to provide a portable, hand-held wet-dry vacuum cleaner which affords improved performance in the liquid mode when held in the angular orientation in which the air inlet opening of the nozzle faces vertically upwardly.
It is a further object of the present invention to provide a portable, hand-held wet-dry vacuum cleaner which achieves the aforesaid improved performance in a manner which is at the same time simple and inexpensive, not adding appreciably, if at all, to the cost of manufacturing the wet-dry vacuum cleaner according to the invention.
Other objects and advantages of the invention will become apparent hereinafter.